The 26-year-old, who can play at left-back as well as on the left side of midfield, bolsters Martin Jol's side until the end of the season.
Emanuelson has 16 caps for Holland and played under Jol during his time at the Ajax helm in 2009/10.
He made 240 appearances for Ajax before moving to AC Milan in January 2011 and went on to help the side win the Serie A title that term.
"It is not easy to get players from AC Milan on a permanent basis," Jol said of Emanuelson after Fulham's 3-1 defeat of West Ham last night.
"I coached him at Ajax. He is a skilful player, very agile. He is very mobile, quick.
"He can play left midfield, wide, play number 10 so I feel we need fresh legs."